Hear from Our Customers
California’s Heavy-Duty Inspection and Maintenance program isn’t optional anymore. If you’re running a 2013 or newer diesel truck over 14,000 pounds on public roads in California, you need semi-annual Clean Truck Check testing to stay compliant with CARB regulations.
Miss a deadline and you’re looking at DMV registration blocks that ground your trucks. Get caught without a valid compliance certificate during a CHP inspection and the fines start at serious numbers—up to $10,000 per vehicle per day. Ports and railyards won’t let you in without proof of compliance either.
The testing itself takes the guesswork out. We use CARB-certified OBD devices to pull diagnostic data from your truck’s computer system. If your truck passes, you get a compliance certificate that’s valid for six months. You can submit passing tests up to 90 days before your deadline, which gives you breathing room if repairs are needed.
This isn’t about adding more paperwork to your day. It’s about keeping your operation moving without the constant worry that one missed deadline or one roadside stop is going to cost you thousands or shut you down completely.
We operate right in South Gate, which means we’re in the middle of LA County’s trucking corridor. You’re not driving out of your way to get this done.
Our testers are CARB credentialed, which means they’ve completed California’s official training course, passed the exam, and renew their credentials every two years. We’re certified specifically for Heavy-Duty Inspection and Maintenance testing on 2013 and newer trucks with a GVWR over 14,000 pounds.
South Gate has one of the highest concentrations of trucking and logistics operations in California. We understand the pressure you’re under to keep trucks moving, meet delivery schedules, and stay on top of regulations that keep changing. That’s why we focus on getting you tested, certified, and back on the road.
When you bring your truck in, we start by confirming it meets the program requirements—2013 or newer model year and over 14,000 pounds GVWR. This isn’t a test for older trucks or lighter vehicles.
We connect a CARB-certified OBD device to your truck’s diagnostic port and pull data directly from the engine’s computer system. The device checks for emission-related fault codes and monitors to make sure your truck’s emission control systems are working properly. The whole process is standardized by CARB, so every credentialed tester in California is running the same checks.
If your truck passes, you get a compliance certificate on the spot. That certificate is what you’ll need if you’re stopped by CHP or entering a port or railyard. It’s also what keeps the DMV from blocking your registration renewal.
If your truck doesn’t pass, we’ll tell you exactly what triggered the failure. You’ll have time to get repairs done and come back for a retest. Remember, you can submit a passing test up to 90 days before your compliance deadline, so you’re not scrambling at the last minute if something needs fixing.
Ready to get started?
California’s HD I/M program kicked into full enforcement on October 1, 2024. If you’re operating a 2013 or newer diesel truck or diesel hybrid over 14,000 pounds GVWR on California public roads, you’re required to complete emissions testing every six months.
The first compliance deadline was January 1, 2025. After that, you’re on a semi-annual schedule based on your vehicle’s specific compliance date. Miss a deadline and the DMV can block your registration renewal. Get caught operating without a valid certificate and you’re facing fines that can hit $10,000 per vehicle per day.
In South Gate, where trucking is a major part of the local economy, staying compliant isn’t just about avoiding fines. It’s about protecting your ability to operate. Shippers are also on the hook—they can be fined up to $10,000 for hiring carriers that aren’t compliant with CARB diesel compliance requirements.
The annual compliance fee is $31.18 per vehicle as of 2025. That fee is separate from the testing itself, but it’s part of staying legal under California CARB compliant regulations. And starting in October 2027, testing frequency increases to four times per year for OBD-equipped vehicles, so the requirements are only getting tighter.
Only trucks that are model year 2013 or newer and have a gross vehicle weight rating over 14,000 pounds are required to complete Clean Truck Check testing under California’s Heavy-Duty Inspection and Maintenance program. This includes diesel trucks and diesel hybrids operating on California public roads.
If your truck is older than 2013 or weighs less than 14,000 pounds GVWR, this program doesn’t apply to you. The program also covers California-registered motorhomes over 14,000 pounds, as well as out-of-state trucks that operate in California.
The key thing to understand is that this is a CARB emissions testing requirement specifically for newer heavy-duty vehicles. Older trucks fall under different regulations, and lighter commercial vehicles aren’t part of this program at all.
Right now, you need to complete Clean Truck Check testing every six months. Your first deadline depends on when your vehicle was registered in the program, and after that, you’re on a semi-annual schedule.
You can submit a passing test up to 90 days before your compliance deadline, which gives you a buffer if your truck needs repairs. That 90-day window is important because if your truck fails, you’ll need time to fix whatever triggered the failure and come back for a retest.
Starting October 1, 2027, the testing frequency increases to four times per year for OBD-equipped vehicles. That’s CARB’s timeline, not ours, but it means the compliance schedule is getting tighter. For now, focus on meeting your semi-annual deadlines and keeping your compliance certificate current.
If your truck fails, we’ll tell you exactly what caused the failure. Usually it’s an emission-related fault code or a monitor that isn’t ready. You’ll need to get the issue repaired and then come back for a retest.
The good news is that you can test up to 90 days before your deadline, so if you fail, you have time to get repairs done without missing your compliance date. If you wait until the last minute and fail, you’re in a tougher spot because the DMV can block your registration if you miss the deadline.
Failing the test doesn’t mean you’re immediately fined, but operating without a valid compliance certificate after your deadline passes can lead to fines of up to $10,000 per vehicle per day if you’re caught during a roadside inspection. Get it fixed, get retested, and keep your certificate current.
You can get your Clean Truck Check done at any CARB-credentialed testing location in California. The testing process is standardized, so it doesn’t matter where you go as long as the tester is credentialed.
That said, if you’re based in or around South Gate, coming to us makes more sense than driving across LA County. You’re already operating in this area, so getting tested here keeps your truck close to your routes and saves you time.
Some testing stations offer mobile services where they come to your yard or location. We’re a fixed location in South Gate, which works well for owner-operators and small fleets that are already running through this part of LA County regularly.
The cost of the actual emissions test varies by location and provider. You’ll need to contact us directly for current pricing on the Clean Truck Check service itself.
What’s separate from the test is the annual compliance fee that CARB charges, which is $31.18 per vehicle as of 2025. That fee goes to the state, not to the testing station, and it’s required to keep your vehicle registered in the HD I/M program.
When you get tested, you’re paying for the OBD diagnostic check using CARB-certified equipment and the compliance certificate if you pass. If you fail and need a retest, there may be an additional fee for the retest depending on our policy. The test itself doesn’t include repairs—if something needs fixing, that’s a separate cost you’ll handle with a mechanic.
Bring your vehicle registration so we can verify the truck’s information matches what’s in the CARB system. We’ll need to confirm the model year and GVWR to make sure your truck is eligible for testing under the HD I/M program.
If you’ve had recent repairs done related to emission systems, bring any paperwork or receipts. It won’t affect the test itself, but it’s helpful context if your truck fails and we need to figure out what’s going on.
Make sure your truck’s check engine light isn’t on when you arrive. If it is, that’s an automatic failure because it indicates an active fault code. Get that checked out and cleared before you come in for testing. Other than that, just bring the truck and your registration, and we’ll handle the rest.
Local Resources
Useful Links
Other Services we provide in South Gate
